U.S. patent number 4,551,501 [Application Number 06/686,866] was granted by the patent office on 1985-11-05 for crystalline propylene polymer composition.
This patent grant is currently assigned to Sumitomo Chemical Company, Limited. Invention is credited to Masahiro Kakugo, Junpei Kojima, Akinobu Shiga, Kizuku Wakatsuki.
United States Patent |
4,551,501 |
Shiga , et al. |
November 5, 1985 |
Crystalline propylene polymer composition
Abstract
A crystalline propylene polymer composition having excellent
transparency and rigidity comprising a blend of a crystalline
polypropylene with a polymer of a vinyl cycloalkane having at least
6 carbon atoms. The composition contains 0.05 weight ppm to 10,000
weight ppm of the vinyl cycloalkane unit.
Inventors: |
Shiga; Akinobu (Tokyo,
JP), Kakugo; Masahiro (Chiba, JP), Kojima;
Junpei (Chiba, JP), Wakatsuki; Kizuku (Chiba,
JP) |
Assignee: |
Sumitomo Chemical Company,
Limited (Osaka, JP)
|
Family
ID: |
17179405 |
Appl.
No.: |
06/686,866 |
Filed: |
December 27, 1984 |
Foreign Application Priority Data
|
|
|
|
|
Dec 27, 1983 [JP] |
|
|
58-248520 |
|
Current U.S.
Class: |
525/88; 525/216;
525/297; 525/89; 525/95 |
Current CPC
Class: |
C08F
297/08 (20130101); C08F 297/083 (20130101); C08L
23/10 (20130101); C08L 53/00 (20130101); C08L
23/10 (20130101); C08L 23/20 (20130101); C08L
53/00 (20130101); C08L 23/20 (20130101); C08L
23/10 (20130101); C08L 23/10 (20130101); C08L
53/00 (20130101); C08L 53/00 (20130101); C08L
53/00 (20130101); C08L 53/00 (20130101); C08L
23/20 (20130101); C08L 2666/02 (20130101); C08L
2666/06 (20130101); C08L 2666/02 (20130101); C08L
2666/06 (20130101); C08L 2666/04 (20130101); C08L
2666/24 (20130101) |
Current International
Class: |
C08L
23/00 (20060101); C08L 23/10 (20060101); C08L
53/00 (20060101); C08L 023/12 (); C08L 023/14 ();
C08L 053/00 () |
Field of
Search: |
;525/216,95,89,88,297 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Journal of Polymer Science, vol. XXXIX, Issue 135, (1959),
"Nucleation Effects in High Polymers", pp. 543-545..
|
Primary Examiner: Seccuro; Carman J.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak, and
Seas
Claims
What is claimed is:
1. A crystalline propylene polymer composition comprising a blend
of a crystalline polypropylene with a polymer of a vinyl
cycloalkane having at least 6 carbon atoms, said composition
containing 0.05 weight ppm to 10,000 weight ppm of the vinyl
cycloalkane unit.
2. A composition of claim 1, wherein said crystalline polypropylene
is a homopolymer of propylene.
3. A composition of claim 1, wherein said crystalline polypropylene
is a random copolymer of propylene with another .alpha.-olefin
having 2 to 18 carbon atoms.
4. A composition of claim 1, wherein said crystalline polypropylene
is a block copolymer of propylene with another .alpha.-olefin
having 2 to 18 carbon atoms.
5. A composition of claim 1, wherein said polymer of vinyl
cycloalkane is a homopolymer of a vinyl cycloalkane having at least
6 carbon atoms.
6. A composition of claim 1, wherein said polymer of vinyl
cycloalkane is a block copolymer of a vinyl cycloalkane having at
least 6 carbon atoms with an .alpha.-olefin.
7. A composition of claim 6, wherein said .alpha.-olefin is
propylene.
8. A composition of claim 1, wherein said vinyl cycloalkane is
vinyl cyclobutane, vinyl cyclopentane, vinyl-3-methyl cyclopentane,
vinyl cyclohexane, vinyl-2-methyl cyclohexane, vinyl-3-methyl
cyclohexane, or vinyl norbornane.
9. A composition of claim 8, wherein said vinyl cycloalkane is
vinyl cyclopentane or vinyl cyclohexane.
10. A composition of claim 1, wherein said composition contains 0.5
weight ppm to 5,000 weight ppm of the vinyl cycloalkane unit.
Description
FIELD OF THE INVENTION
This invention relates to a propylene polymer composition having
excellent crystallinity.
BACKGROUND OF THE INVENTION
A polypropylene is a synthetic resin which has high rigidity and
mechanical strength but of which rate of crystallization is
relatively slow. In some applications, therefore, its crystallinity
after molding is low and its rigidity is reduced accordingly. Or
because of the formation of relatively large spherulites, molded
articles of the polymer have inferior transparency and may have a
debased commercial value.
Some attempts have been made heretofore to improve the
crystallinity and transparency polypropylene. For example, it is
known that when an aluminum or sodium salt of an aromatic
carboxylic acid (Japanese Laid-open Patent Publication No.
80329/1983) or an aromatic carboxylic acid, an aromatic metal
phosphate or a sorbitol derivative (Japanese Patent Publication No.
12460/1980 and Japanese Laid-Open Patent Publication No.
129036/1983) is added, it becomes an agent for forming a crystal
nucleus (to be referred to as a nucleating agent), and reduces the
aforesaid problem. Among these nucleating agent, the sorbitol
derivative exhibits a particularly good nucleating effect, but is
limited in its use because it bleeds out from the resin to
contaminate rolls during film formation and give an offensive odor
during processing. The aluminum salt of an aromatic carboxylic acid
which is frequently used in general acts as a nucleating agent, but
has a very small effect of improving the transparency of the
polypropylene. Furthermore, a film formed from a polypropylene
containing this aluminum salt develops numerous voids.
Japanese Patent Publication No. 32430/1970 describes that to
improve the transparency of polypropylene, a three-component
copolymer is prepared by copolymerizing propylene, an
.alpha.-olefin having 4 to 18 carbon atoms and 3-methylbutene-1.
The transparency of this copolymer is still unsatisfactory. Even
when such a 3-methylbutene-1 copolymer is blended with a
polypropylene, the effect of improving the transparency of the
polypropylene is unsatisfactory.
SUMMARY OF THE INVENTION
In view of these defects, the present inventors have made extensive
investigations, and have found that the crystallinity and
transparency of a polypropylene can be improved by blending a
crystalline polypropylene with a vinyl cycloalkane polymer. This
discovery has led to the present invention.
According to this invention, there is provided a crystalline
propylene polymer composition comprising a blend of a crystalline
polypropylene with a polymer of a vinyl cycloalkane having at least
6 carbon atoms, said composition containing 0.05 weight ppm to
10,000 weight ppm of the vinyl cycloalkane unit.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a schematic view of a pressing plate to mold a sample
sheet for the measurement of optical properties.
DETAILED DESCRIPTION OF THE INVENTION
The crystalline polypropylene, as used in this invention, denotes a
homopolymer of propylene or a random or block copolymer of
propylene with another .alpha.-olefin having 2 to 18 carbon atoms.
Examples of another .alpha.-olefin having 2 to 18 carbon atoms
include ethylene, butene-1, pentene-1, hexene-1, and octene-1. An
amount of another .alpha.-olefin which is copolymerized with
propylene is up to 50 mole% per mole of propylene.
The vinyl cycloalkane polymer denotes a homopolymer of a vinyl
cycloalkane having at least 6 carbon atoms or a random copolymer of
the vinyl cycloalkane with a small amount (i.e., up to 20 mole% per
mole of the vinyl cycloalkane) of another vinyl cycloalkane or an
.alpha.-olefin or a block copolymer of the vinyl cycloalkane with
an .alpha.-olefin. Examples of the .alpha.-olefin which is
copolymerized with the vinyl cycloalkane are .alpha.-olefins having
2 to 8 carbons such as ethylene, propylene, and butene-1. The vinyl
cycloalkane block copolymer denotes a copolymer of the vinyl
cycloalkane with various .alpha.-olefins obtained by multi-step
polymerization, for example (1) a copolymer obtained by
polymerizing the vinyl cycloalkane in a first step and
homopolymerizing propylene in a second step, (2) a copolymer
obtained by polymerizing the vinyl cycloalkane in a first step and
random copolymerizing propylene with another .alpha.-olefin in a
second step, and (3) a copolymer obtained by homopolymerizing
propylene in a first step, polymerizing the vinyl cycloalkane in a
second step, and homopolymerizing propylene or copolymerizing
propylene with another .alpha.-olefin in a third step. Of these
vinyl cycloalkane polymers, the block copolymers are preferred, and
the block copolymers of the vinyl cycloalkane with propylene as
shown in (1) to (3) are more preferred.
Examples of the vinyl cycloalkane having at least 6 carbon atoms
used to prepare the vinyl cycloalkane polymer include vinyl
cyclobutane, vinyl cyclopentane, vinyl-3-methyl cyclopentane, vinyl
cyclohexane, vinyl-2-methyl cyclohexane, vinyl-3-methyl cyclohexane
and vinyl norbornane, with vinyl cyclopentane and vinyl cyclohexane
being preferred. Examples of another vinyl cycloalkane to be
copolymerized with the vinyl cycloalkane are those listed above for
the vinyl cycloalkane.
In order to obtain the improving effect without changing the
inherent properties of the crystalline polypropylene, the content
of the vinyl cycloalkane unit in the crystalline propylene polymer
composition of this invention should be 0.05 to 10,000 weight ppm,
preferably 0.5 to 5,000 weight ppm, more preferably 0.5 to 1,000
weight ppm.
The crystalline polypropylene and the vinyl cycloalkane polymer
used in this invention can be conveniently produced by using a
catalyst system composed of a titanium compound and an
organoaluminum compound. That is, homopolymerization of propylene
or copolymerization of it with another .alpha.-olefin may be
carried out by known polymerization methods, for example, by slurry
polymerization in a hydrocarbon solvent such as hexane or heptane,
bulk polymerization in liquefied propylene, vapor-phase
polymerization in a propylene gas, etc. The copolymerization of
propylene with another .alpha.-olefin may be random
copolymerization or block copolymerization. The polymerization
temperature is 20.degree. C. to 100.degree. C., and the
polymerization pressure is atmospheric pressure to 60 kg/cm.sup.2
-G. Further, the homopolymerization of the vinyl cycloalkane or the
copolymerization of it with another vinyl cycloalkane or with an
.alpha.-olefin may be carried out preferably in the presence of a
polymerization solvent. Suitable polymerization solvents include
the above vinyl cycloalkane monomers themselves and hydrocarbons
such as butane, hexane, heptane, benzene and toluene. The
polymerization temperature is 20.degree. C. to 100.degree. C., and
the polymerization pressure is atmospheric pressure to 60
kg/cm.sup.2 -G. Examples of the titanium compound are the titanium
trichloride catalysts sold by Toyo Stauffer Co., Ltd., Toho
Titanium Co., Ltd., and Marubeni-Solvay Co., Ltd. The catalysts
comprising magnesium compounds and titanium compounds supported
thereon which are described in, for example, Japanese Laid-Open
Patent Publication Nos. 59916/1982 and 133408/1980 may also be
conveniently used.
The organoaluminum compound is preferably alkyl aluminum compound
represented by the following formula:
wherein X represents a halogen atom, an alkoxy group or a hydrogen
atom, R represents an alkyl group having 1 to 18 carbon atoms, and
a is a number represented by 0.ltoreq.a<3. Specific examples of
the organoaluminum compound include Al(CH.sub.3).sub.3, Al(C.sub.2
H.sub.5).sub.3, Al(C.sub.2 H.sub.5).sub.2 Cl, Al(C.sub.2
H.sub.5).sub.2 Br, Al(C.sub.2 H.sub.5).sub.2 (OC.sub.2 H.sub.5),
Al(C.sub.2 H.sub.5).sub.2 (OC.sub.4 H.sub.9), Al(C.sub.2
H.sub.5)(OC.sub.4 H.sub.9).sub.2, Al(C.sub.2 H.sub.5)Cl.sub.2,
Al(C.sub.4 H.sub.9).sub.3, Al(C.sub.4 H.sub.9).sub.2 Cl, Al(C.sub.6
H.sub.13).sub.3, Al(C.sub.6 H.sub.13).sub.2 Cl and mixtures
thereof.
To improve the stereoregularity of the crystalline polypropylene or
the vinyl cycloalkane polymer, it is possible to add an electron
donor such as carboxylic acid esters, phosphoric acid esters or
silicic acid esters during the polymerization.
The crystalline polypropylene and the vinyl cycloalkane polymer can
be blended by methods usually employed in blending .alpha.-olefin
polymers. Specifically, the powders of the two polymers, the
pellets of two polymers, or a powder of one polymer and pellets of
the other polymer may be mixed in a Henschel mixer or the like, and
melted and kneaded by a Brabender, a roll, a Banbury mixer, a
granulator, etc.
As required, all types of additives normally incorporated in
polypropylenes, such as heat and light stabilizers, antistatic
agents, antioxidants, carbon black, pigments and flame retardants,
may be added to the crystalline propylene polymer composition of
this invention. Furthermore, the composition of this invention may
be mixed with another polymer such as low-density polyethylene,
high-density polyethylene, polybutene or EP (ethylene/propylene)
rubber and filler such as mica and talc
The crystalline propylene polymer composition of this invention may
be molded into a variety of products such as sheets, films,
containers and fibers by known techniques such as injection
molding, pressure forming, vacuum forming, extrusion molding, blow
molding and stretching.
The following examples illustrate the present invention
specifically. It should be noted however that the invention is in
no way limited to these examples.
The various properties including the melt index, light scattering
index (LSI), haze, gloss, [.eta.], and crystallization temperature
shown in these examples were measured by the following
examples.
(1) Melt index:
Measured in accordance with JIS K-6758.
(2) [.eta.]:
Measured at 135.degree. C. in tetralin using an Ubbelohde's
viscometer.
(3) Crystallization temperature:
Measured at a temperature falling speed of 4.degree. C./min. by
means of a differential scanning calorimeter (DSC).
(4) Light scattering index (LSI):
Measured by an LSI tester made by Toyo Seiki K.K. (receiving
scattering transmitting light of 1.2.degree. to 3.6.degree.).
(5) Haze:
Measured in accordance with ASTM D1003.
(6) Gloss:
Measured in accordance with ASTM D532-53T.
(7) Total light transmittance:
Measured by ASTM-D1746-62T.
(8) Internal haze:
The sample sheet was immersed in dimethyl phthalate, and its
internal haze was measured in accordance with ASTM D1003.
(9) Internal total light transmittance:
The sample sheet was immersed in dimethyl phthalate, and its
internal total light transmittance was measured in accordance with
ASTM D1745-62T.
(10) Flexural modulus:
Measured in accordance with ASTM D790-66 on a sample having a
thickness of 5.0 mm obtained by compression molding in accordance
with JIS K-6758.
Sample sheets for the measurement of the optical properties (4) to
(9) were prepared in accordance with the pressing temperature,
pressure and time conditions indicated in JIS K-6758 by using the
pressing plate shown in FIG. 1, i.e., a resin sample was put into a
space surrounded by a 1 mm-thick stainless plate 1 and a 1 mm-thick
aluminum plate 2 and then pressed to prepare the sample sheet. A
numeral 3 represents a 1 mm-thick stainless steel plate.
EXAMPLE 1
(1) Synthesis of a copolymer of vinyl cyclohexane and propylene
To 100 ml of dehydrated and purified n-heptane were successively
added 1.95 g of triethyl aluminum, 675 mg of ethyl p-anisate and
6.0 g of a titanium compound catalyst synthesized in accordance
with Example 1 of Japanese Laid-Open Patent Publication No.
59916/1982. The mixed solution was then heated to 50.degree. C.,
and then 50 ml of vinyl cyclohexane was added. The vinyl
cyclohexane was polymerized for 15 minutes. The resulting polymer
slurry was washed four times with 200 ml of n-heptane to remove the
unreacted vinyl cyclohexane, triethyl aluminum and ethyl p-anisate.
The n-heptane was removed from the washed active slurry by
distillation under reduced pressure to obtain 7.8 g of a powder of
polyvinyl cyclohexane containing the active catalyst. The amount of
polyvinyl cyclohexane formed was 0.30 g per gram of the charged
titanium compound catalyst.
By using 1.06 g of the vinyl cyclohexane polymerization catalyst,
0.75 g of triethyl aluminum, 0.237 g of methyl p-toluate and 1500
ml of n-heptane, propylene was polymerized in a 5-liter stainless
steel autoclave at a temperature of 70.degree. C. under a pressure
of 6 kg/cm.sup.2 -G for 40 minutes using hydrogen in a
concentration of 1.5% by volume. After the polymerization, 50 ml of
n-butanol was added to stop the polymerization. The polymer slurry
was taken out, and filtered to separate the polymer powder from the
solvent. The polymer powder was washed with 500 ml of 1N
hydrochloric acid and then with methanol until the washings became
neutral. The powder was dried and then weighed. Its amount was
found to be 840 g. The amount of propylene polymerized was 1030 g
per gram of the titanium compound catalyst. The powdery copolymer
had an [.eta.] of 1.93 dl/g. The vinyl cyclohexane unit content of
the copolymer powder, calculated from the amount of vinyl
cyclohexane polymerized per gram of the titanium compound catalyst,
was 290 weight ppm.
(2) Preparation of a propylene polymer composition and a molded
article
One hundred parts by weight of propylene homopolymer having a melt
index of 1.0 was mixed with 0.5 part by weight of the copolymer
prepared in (1) above, 0.2 part by weight of BHT (2,6-di-tertiary
butyl hydroxytoluene) and 0.05 part by weight of calcium stearate
as stabilizers and 0.05 part by weight of Irganox.RTM. 1010
(antioxidant made by Ciba-Geigy AG;
tetrabis[methylene-3(3',5'-di-t-butyl-4-hydroxyphenyl)propionate]methane)
by a Henschel mixer. The mixture was pelletized by a usual method
using an extruder having a screw diameter of 40 mm. The pellets
were melted and pressed by a hot press-forming machine kept at
230.degree. C., and then cooled by a cold press having water at
30.degree. C. circulated therethrough, to form a sheet having a
thickness of 1 mm. The press sheet was quite odor-free, and had a
haze of 63.0%, an LSI of 0.2% and a gloss of 95%. The composition
had a crystallization temperature of 126.8.degree. C.
EXAMPLES 2 TO 4
Example 1 was repeated except that the amount of the vinyl
cyclohexane copolymer blended was changed to 1 part by weight
(Example 2), 2 parts by weight (Example 3) or 10 parts by weight
(Example 4). The crystallization temperatures, LSI and haze values
of the products are shown in Table 1.
COMPARATIVE EXAMPLE 1
For comparison, the haze, LSI, gloss and crystallization
temperature of a press sheet of propylene homopolymer in the
absence of the copolymer obtained in Example 1-(1) were measured.
They were 52.5%, 40.5%, 74%, and 116.5.degree. C.,
respectively.
TABLE 1 ______________________________________ Example Content of
Difference in Sum of (Ex.) or Polyvinyl Crystal- Crystal- Haze
Comparative Cyclo- lization lization and Example hexane Temperature
Temperature Gloss (CEx.) (wt. ppm) (.degree.C.) (.degree.C.) (%)
______________________________________ Ex. 1 1.5 126.8 10.3 63.2
Ex. 2 3 127.0 10.5 55.0 Ex. 3 6 126.6 10.1 51.0 Ex. 4 29 130.0 13.5
37.5 CEx. 1 -- 116.5 -- 93.0
______________________________________
The data given in Table 1 demonstrate that the polyvinyl
cyclohexane-containing polypropylene has a high crystallization
temperature, a marked small light scattering intensity of the
transmitted light and excellent transparency.
EXAMPLES 5 AND 6
To a mixture of 10 ml of n-heptane and 5 ml of vinyl cyclohexane
were added 0.157 g of titanium trichloride (a product of
Marubeni-Solvay Co., Ltd.) and 0.3 g of triethyl aluminum, and the
vinyl cyclohexane was polymerized at 50.degree. C. for 45 minutes.
The polymerization was stopped by adding methanol. The product was
washed with HCl-methanol to give 2.5 g of polyvinyl cyclohexane.
The resulting polyvinyl cyclohexane (0.1 g in Example 5, and 0.01 g
in Example 6) was dissolved in 20 ml of carbon tetrachloride. The
solution was uniformly impregnated in 20 g of a powder of propylene
homopolymer having a melt index of 27. The carbon tetrachloride was
then removed by drying under reduced pressure. The residue was
kneaded by a roll with the same proportions of the stabilizers and
antioxidant (BHT, calcium stearate and Irganox.RTM. 1010) as used
in Example 1. The optical properties and crystallization
temperature of the resulting propylene polymer composition were
measured. The results are shown in Table 2 together with those
values of propylene homopolymer without the blending of polyvinyl
cyclohexane (Comparative Example 2). It is seen that the blends of
a homopolymer of vinyl cyclohexane and propylene homopolymer also
exhibited improved transparency and gloss.
TABLE 2 ______________________________________ Example Content of
(Ex.) or Polyvinyl Comparative Cyclo- Crystallization Example
hexane Temperature Haze LSI Gloss (CEx.) (wt. ppm) (.degree.C.) (%)
(%) (%) ______________________________________ Ex. 5 5,000 130.9
63.5 1.6 85 Ex. 6 500 129.9 60.4 0 88 CEx. 2 -- 120.6 66.0 27 71
______________________________________
COMPARATIVE EXAMPLE 3
A copolymer of 4-methylpentene-1 and propylene was synthesized as
in Example 1 except that 4-methylpentene-1 was used instead of
vinyl cyclohexane.
One hundred parts by weight of the propylene homopolymer having a
melt index of 27 shown in Comparative Example 2 (crystallization
temperature: 120.6.degree. C., haze: 66%, gloss: 71%) was mixed
with 0.5 part by weight of the above copolymer to give a propylene
polymer composition containing 122 ppm of 4-methylpentene-1 unit. A
press sheet formed from this composition had a haze of 71.4%, an
LSI of 20.0%, a gloss of 75% and a crystallization temperature of
122.0.degree. C. The difference of this crystallization temperature
from that of the propylene homopolymer was 1.4.degree. C. It was
found that poly-4-methylpentene-1 hardly showed a nucleating action
and did not show a substantial improvement of the transparency of
the propylene polymer.
EXAMPLE 7
To 20 ml of dehydrated and purified n-heptane were successively
added 0.6 millimole of diethyl aluminum chloride and 1.10 g of the
titanium trichloride catalyst (a product of Marubeni-Solvay Co.,
Ltd.). The mixed solution was heated to 60.degree. C. Then, 10 ml
of vinyl cyclohexane was added and polymerized for 15 minutes.
There are obtained a catalyst containing 1.26 g of polymerized
vinyl cyclohexane per gram of the titanium trichloride catalyst.
Propylene was homopolymerized in the same way as in Example 1 using
the resulting catalyst and diethyl aluminum chloride to give
polypropylene containing 0.14% by weight of vinyl cyclohexane unit
and having an [.eta.] of 2.2 dl/g.
The resulting copolymer (0.5 part by weight) was added to 100 parts
by weight of propylene homopolymer having a melt index of 0.5
(crystallization temperature: 118.3.degree. C., a 1 mm-thick press
sheet prepared from the propylene homopolymer had a haze of 54.3%,
an LSI of 41.0% and a gloss of 69%), and the same stabilizers and
antioxidant as in Example 1 were added. They were kneaded by a
Brabender to give a crystalline propylene polymer composition
containing 7 weight ppm of the vinyl cyclohexane polymer. The
composition had a crystallization temperature of 130.2.degree. C.
which was higher by 11.9.degree. C. than that of the propylene
homopolymer. A 1 mm-thick press sheet prepared from the composition
showed a haze of 50.1%, an LSI of 2.0% and a gloss of 80%,
respectively.
EXAMPLE 8
A propylene copolymer having an [.eta.] of 6.0 dl/g and containing
2.22% by weight of vinyl cyclohexane unit was produced in the same
way as in Example 7 by polymerizing 4.88 g of vinyl cyclohexane per
gram of the titanium trichloride catalyst in a first step and
homopolymerizing propylene in a second step. The resulting
copolymer (2% by weight) was blended with 98% by weight of the same
propylene homopolymer (MI 0.5) as used in Example 7 in the same way
as in Example 7 to give a propylene polymer composition. The
optical properties of the composition were measured and the results
are shown in Table 3.
COMPARATIVE EXAMPLES 4 TO 10
For comparison, in each run, a composition composed of the
propylene homopolymer and a propylene copolymer containing 0.3 to
2.0 g of each of the vinyl compounds shown in Table 3 polymerized
per gram of the titanium trichloride catalyst was prepared in the
same way as in Example 7 except that the aforesaid vinyl compound
was used instead of vinyl cyclohexane. The optical properties of
the composition were measured, and the results are shown in Table
3.
COMPARATIVE EXAMPLES 11 TO 14
In each run, the same procedure as in Example 7 was repeated except
that allylbenzene or styrene was used instead of vinyl cyclohexane,
and when allylbenzene or styrene was polymerized, triethyl aluminum
was used instead of diethyl aluminum chloride. The optical
properties of the resulting composition were measured, and the
results are shown in Table 3.
The results in Comparative Example 3 and Comparative Examples 4 to
14 show that even though a high melting polymer
(poly-4-methylpentene-1: 238.degree. C., poly-3-methylbutene-1:
303.degree. C., polyvinyl cyclohexane: 418.degree. C.,
poly-3-methylpentene-1: 273.degree. C., polyallylbenzene:
208.degree. C., polystyrene: 242.degree. C.) is merely contained in
polypropylene, the optical properties of the polypropylene cannot
be improved.
TABLE 3
__________________________________________________________________________
Vinyl compound/propylene Optical Properties copolymer Content of
Total Light Example (Ex.) Blending vinyl compound trans- or
Comparative [.eta.] Amount in the composition Haze LSI mittance
Gloss Example (CEx.) Vinyl compound (dl/g) (%) (wt. ppm) (%) (%)
(%) (%)
__________________________________________________________________________
Base -- -- -- -- 54 41 86 69 polypropylene Ex. 7 Vinyl cyclohexane
2.2 0.5 7 50 2 86 80 Ex. 8 " 6.0 2 444 30 1 86 98 CEx. 4
3-Methylbutene-1 1.86 0.5 2 82 7 90 72 CEx. 5 " " 2 8 82 4 91 77
CEx. 6 " " 50 200 80 4 87 75 CEx. 7 Vinyl cyclohexene 1.9 0.5 3 74
18 89 68 CEx. 8 " " 50 300 85 10 -- -- CEx. 9 3-Methylpentene-1 2.0
0.5 10 75 7 88 74 CEx. 10 " " 50 1000 82 3 85 66 CEx. 11
Allylbenzene 2.0 0.5 75 65 29 88 60 CEx. 12 " " 50 7500 95 0 64 72
CEx. 13 Styrene 2.1 0.5 38 80 9 90 68 CEx. 14 " " 50 3800 94 0 --
--
__________________________________________________________________________
EXAMPLE 9
In the same way as in Example 1-(1), a propylene copolymer
containing 0.72% by weight of a vinyl cyclohexane homopolymer
polymerized in an amount of 3.0 g per gram of the titanium compound
was obtained. The copolymer (10% by weight) and 90% by weight of a
propylene/ethylene random copolymer having a melt index of 7.2 and
an ethylene content of 3.2% by weight were kneaded by a Brabender,
and the optical properties of the resulting composition were
measured. The results are shown in Table 5.
COMPARATIVE EXAMPLE 15
A composition having the same ethylene content as the composition
of Example 9 was prepared by blending 10% by weight of a propylene
homopolymer having a melt index of 2.0 with the same
propylene/ethylene random copolymer used in Example 9. The optical
properties of a press sheet formed from the composition were
measured, and the results are shown in Table 5.
The resulting composition had a higher haze and LSI than the
composition of Example 9 containing polyvinyl cyclohexane, and
exhibited poor transparency.
EXAMPLES 10 TO 13 AND COMPARATIVE EXAMPLES 16 TO 26
Using the titanium trichloride catalyst (a product of
Marubeni-Solvay Co., Ltd.) and diethyl aluminum chloride, three
copolymers (A)-1, (A)-2 and (A)-3 shown below were prepared.
Copolymer (A)-1
Obtained by homopolymerizing vinyl cyclohexane in an amount of 1 g
per gram of the titanium trichloride catalyst in a first step, and
homopolymerizing propylene in an amount of 752 g per gram of the
titanium trichloride catalyst in a second step.
Copolymer (A)-2
Obtained by homopolymerizing 3-methylbutene-1 in an amount of 0.31
g per gram of the titanium trichloride catalyst in a first step and
homopolymerizing propylene in an amount of 199 g per gram of the
titanium trichloride catalyst in a second step.
Copolymer (A)-3
Obtained by homopolymerizing 3-methylpentene-1 in an amount of 1.2
g per gram of the titanium trichloride catalyst, in a first step,
and homopolymerizing propylene in an amount of 800 g per gram of
the titanium trichloride catalyst in a second step.
Each of these copolymers was blended with a propylene homopolymer
having a melt index of 2.0, a propylene/ethylene random copolymer
(MI 8.4, ethylene content 5.4% by weight) or a propylene/n-butene-1
random copolymer (melt index: 3.0, butene content: 19% by weight)
in the proportions shown in Table 4. The properties of the
resulting compositions were measured, and the results are shown in
Table 5.
TABLE 4 ______________________________________ Unit: % by weight
Propylene Propylene/ Propylene/ Copolymer Homo- Ethylene Butene-1
(A) polymer Copolymer Copolymer
______________________________________ Example 10 (A)-1 20 -- 80 --
Comparative -- 20 80 -- Example 16 Comparative (A)-2 20 -- 80 --
Example 17 Comparative (A)-3 20 -- 80 -- Example 18 Example 11
(A)-1 20 50 -- 30 Example 12 (A)-1 70 -- -- 30 Comparative -- 70 --
30 Example 19 Comparative (A)-2 20 50 -- 30 Example 20 Comparative
(A)-2 70 -- -- 30 Example 21 Comparative (A)-3 20 50 -- 30 Example
22 Comparative (A)-3 70 -- -- 30 Example 23 Example 13 (A)-1 20 --
-- 80 Comparative -- 20 -- 80 Example 24 Comparative (A)-2 20 -- --
80 Example 25 Comparative (A)-3 20 -- -- 80 Example 26
______________________________________
TABLE 5
__________________________________________________________________________
Example Optical Properties (Ex.) or Composition Total Internal Com-
Vinyl .alpha.-Olefine Inter- Light Total parative Compound Vinyl
Copoly- nal Trans- Light Trans- Flexural Example of copolymer
Compound [.eta.] merized Haze Haze LSI mittance mittance Gloss
Modulus (CEx.) (A) (wt. ppm) (dl/g) (wt %) (%) (%) (%) (%) (%) (%)
(kg/cm.sup.2)
__________________________________________________________________________
Ex. 9 Vinyl 720 Ethylene 2.9 28 3 85 102 cyclohexane CEx. 15 -- --
" 2.9 42 27 86 91 Ex. 10 vinyl 270 1.8 " 4.3 36 25 7 78 74 11900
cyclohexane CEx. 16 -- -- 1.9 " 4.3 65 60 23 84 61 9800 CEx. 17
3-Methyl- 310 1.7 " 4.3 66 59 4 83 70 10500 butene-1 CEx. 18
3-Methyl- 300 1.9 " 4.3 70 66 4 86 76 10400 pentene-1 Ex. 11 Vinyl
270 2.2 n-Butene-1 5.7 46 38 6 80 77 11200 cyclohexane Ex. 12 Vinyl
930 2.0 " 5.7 34 24 7 77 89 15300 cyclohexane CEx. 19 -- -- 2.2 "
5.7 68 62 24 84 63 10900 CEx. 20 3-Methyl- 310 2.1 " 5.7 83 81 3 87
64 12100 butene-1 CEx. 21 3-Methyl- 1100 1.8 " 5.7 83 81 3 82 69
11100 butene-1 CEx. 22 3-Methyl- 300 2.2 " 5.7 79 78 4 87 66 11800
pentene-1 CEx. 23 3-Methyl- 1000 2.3 " 5.7 80 78 3 84 67 12300
pentene-1 Ex. 13 Vinyl 270 2.1 " 15.2 34 24 5 79 83 91 10100
cyclohexane CEx. 24 -- -- 2.2 " 15.2 60 55 13 83 84 74 8100 CEx. 25
3-Methyl- 310 2.1 " 15.2 68 63 3 85 90 66 9200 butene-1 CEx. 26
3-Methyl- 300 2.0 " 15.2 71 69 3 86 90 67 8400 pentene-1
__________________________________________________________________________
It is seen from the above results that the propylene polymer
compositions containing polyvinyl cyclohexane had excellent
rigidity and optical properties. On the other hand, the
compositions containing poly-3-methylbutene-1 or
poly-3-methylpentene-1 showed some improvement in rigidity, gloss
and transmittance, but had a large haze, and therefore, was
unsatisfactory for practical application.
EXAMPLE 14
A polypropylene composition was prepared from 100 parts by weight
of a propylene/ethylene block copolymer having a melt index of 45
and a flexural modulus of 12,000 kg/cm.sup.2 (the propylene
homopolymer portion 75% by weight) and 0.5 part by weight of the
vinyl cyclohexane/propylene copolymer obtained in Example 7. The
flexural modulus of the composition was found to be 13,400
kg/cm.sup.2. The inclusion of only 7 wt. ppm of the vinyl
cyclohexane polymer gave a propylene polymer composition having
very high crystallinity.
EXAMPLE 15
A propylene copolymer composition containing 500 weight ppm of
vinyl cyclopentane was obtained in the same way as in Example 7
except that vinyl cyclopentane was used instead of vinyl
cyclohexane. This composition had a haze of 39% and an LSI of
0.4%.
While the invention has been described in detail and with reference
to specific embodiments thereof, it will be apparent to one skilled
in the art that various changes and modifications can be made
therein without departing from the spirit and scope thereof.
* * * * *